On a Wurlitzer electric piano the reed bar is the large metal bracket which houses the reeds. It is located across the entire piano, usually underneath the damper assembly. Its main functions are as follows:
- To correctly support and align the reeds so they can be correctly struck by the piano action. It does this by the reeds being aligned directly above the note of the hammer which strikes it.
- To house the electrostatic pickup comb, which is responsible for transferring the acoustic tone of the hammer striking the reed, converting it to electrical energy and sending this to the preamplifier.
- To be made of a resonant property that allows reeds to sustain for a when struck. For this the reed bar is a particular density and weight, which contributes significantly to the weight of a Wurlitzer piano.
There are technically two reed bars on a Wurlitzer piano, one for the bass section and one for the treble section. The change of this is at E to F above middle C. Each of these bars is fixed to the action by four screws at each corner. The two reed bars are connected by metal brackets which have wires connecting to the amplifier, or in the case of 200A pianos, a preamp which connects to the main amplifier. At the back of this middle section is the sustain pedal mechanism. This lifts the damper assemble when the attached foot pedal is pressed.
The pickups and preamplifier sections of the reed bar are high voltage. It carries 150V of DC electricity. Always turn the power off before removing or adjusting a reed or cleaning this area. The reed bar should be grounded at the keyboard end where the reed screws are for safety, along with all metal brackets that support it.
If certain reeds in the Wurlitzer are experiencing a dullness or poor sustain, then shimming the reed bar may help. At each corner where the reed bar so screwed down, there might be paper shims/punchings underneath. This to level the reed bar to stop it from flexing. Because the reed bar is so resonant, the slightest flex can change the tone in a given area. Making the reed bar perfectly level can alleviate this issue. It is similar concept to fixing a wobbling table by putting a wedge underneath one of the legs.
The reeds themselves are screwed into the keyboard end of the reed bar by the reed bar screw. Debris underneath the reed bar screw can sometimes lead to poor sustain of notes. Removing the reed in question and cleaning the need bar with isopropyl alcohol can sometimes help.
Quality of the reed bar varied during Wurlitzer production, with the so called ‘green damper’ (so-called because of the green felt used on top of the damper arms) era of 200A pianos tending to have reed bars that have greater inconsistencies of note sustain and tone. These can be mostly rectified with good regulation, but worth noting.
The reed bar is occasionally called the harp, though this is a term usually given to the somewhat similar part of a Rhodes piano.
